1. Field of the Invention
The present invention relates to an automatic focusing camera, particularly, an autofocus camera in which a lens driving system is actuated in accordance with AF (auto focus) data to move a focus adjusting lens through a drive transmitting means to thereby effect the focus adjustment.
2. Description of Related Art
Generally speaking, in a known automatic focusing camera having an AF function, a focus adjusting lens of a taking lens assembly is moved in the optical axis direction thereof by a lens driving system provided in a camera body to control the focus. If the taking lens assembly is an interchangeable lens of a single lens reflex camera, a joint shaft (body joint shaft) which projects from a body mount of the camera body and which is rotated by the lens driving system is engaged by a joint shaft (lens joint shaft) provided on a lens mount of the interchangeable lens to transmit the rotational force.
There are two AF data detecting systems, i.e., an active system in which measuring light is emitted toward an object to be taken, and a passive system in which light transmitted through the taking lens is used to detect the AF data. In a known passive type automatic focusing camera, automatic focusing can not be effected when the object to be taken is dark or when an object contrast can not be detected. In such a case, a photographer actuates a manual switch to disconnect the body joint shaft from the lens joint shaft, so that a focus adjusting ring can be manually rotated to control the focus.
It is necessary for a photographer to shift the position in which he or she holds the camera upon actuating the manual switch and then return the camera to its original position in which a picture is to be taken after the switching operation of the manual switch is completed. However, it is difficult for the photographer to reproduce the same composition after returning the camera to its original position. In particular, in the case of a moving object, the photographer may miss a shutter chance.